Pin shear

I didn't really like the pin solution myself. I put my kit together and run it for a couple hours to see if the pin was getting damaged. It was becoming noticeably deformed. I pulled the motor off and filled the socket with JB weld. I then let it cure for a few minutes before greasing the motor's post and pushing it into the socket (and putting the pin back in). After letting it cure for a couple days I fired it up and have had no problems since. The motor is easily removable and the fit is tight.

The pin is intentional by design. It was meant to crush if the motor was overloaded. As it turns out, there was a non-negligible degree of variation in the way it was installed and the tolerance of the shaft, pin, and socket which made this method less reliable than I'd hoped. I'm transitioning to a square drive shaft and a circuit breaker instead.

The trouble with filling it with JB weld is you lose both overload protection and the ability to cope with misalignment. Not the worst thing ever, but just be aware.

9mm x 9mm square drive shaft (3/8" socket is 9.5mm x 9.5mm). Push to reset circuit breaker set at the stall current so that if it ever stalls, the motor is disabled.

It's been on my "to-do" for a while now, but I've been playing catchup ever since the KS ended.

Indeed. I'm not too worried about the motor dying, but a circuit breaker certainly sounds better than a physical component "breaking" to protect the motor. If nothing else, resetting a breaker is less work than replacing the washer.

But where does one get a adjustable circuit breaker?

Tim said:

"Push to reset circuit breaker set at the stall current so that if it ever stalls, the motor is disabled."

I know how to make a current sense circuit but what would the stall current be?

Ralph

But only if you know what you are doing.

I know how to get the run current with a ohmmeter and ohm's law but not the stall current.

How would ohm's law know the load?

Ralph